Each year, there are over 2 million state child protective service (CPS) investigations of suspected maltreatment, but limited evidence-based services that reduce the high rates of developmental and health- related impairments for CPS-identified children. This response to NIH Exploratory Developmental Research Grant Program (R21: PA-10-069) examines the effects of an evidence-supported intervention model with CPS- identified children and families referred to services within a statewide children's behavioral health system of care. A promising practice to increase service access and reduce subsequent impairments for CPS-identified children is the wraparound service model (WSM). This model uses a family-centered, team-based planning process to provide individualized community-based services and natural supports for children and families. Increasingly, states use the WSM with child welfare populations, despite limited research on its effectiveness, particularly within CPS. This study employs a rigorous quasi-experimental design to compare 250 CPS- identified children referred to either the WSM or traditional non-wraparound services (NWS) in a statewide system of care for children and families. Previous research has shown that individuals referred to NWS in this study site are comparable to those referred to the WSM on a range of child and family domains. The present study examines the effectiveness of the WSM through a novel application of propensity score methods with a prospective cohort design to adjust for potential group differences due to selection bias across conditions. Propensity score methods adjust for factors that influence assignment to study conditions and re-balance characteristics of the treatment and comparison groups before hypothesis testing. One aim of this study is to test 6-month intervention effects of the WSM on improvements in child and family clinical, behavioral, and functional outcomes. Another aim is to study hypothesized mediators (enhanced fidelity to WSM principles, increased family support, and greater engagement in community services) on observed WSM effects. The results of this innovation will: a) inform the development of systems-level interventions using the WSM with CPS populations, b) confirm the feasibility and appropriateness of propensity score methods to conduct effectiveness trials in public systems where randomization is not practical or possible; c) advance the WSM research base for CPS-identified populations so as to inform states currently investing resources in this model; d) lead to the development of an R01 study to investigate the effectiveness of the WSM with maltreated children across one or more of the multiple states investing in this service model; e) promote the emergence of new standards of practice and public policy for CPS-identified children; and f) advance multiple NIMH priorities to develop and test innovative designs for intervention research, strengthen the use of mental health interventions in diverse community settings, promote more personalized treatment approaches, and use state- level administrative data for policy relevant mental health services research (e.g., RFA-MH-09-050). PUBLIC HEALTH RELEVANCE: The wraparound service model is being implemented in sites across the country, and there is significant interest in the effects of the model with diverse populations. Because the study involves a statewide, system-level initiative to provide wraparound services to a high-risk population of children and families, the proposed study has the potential to produce relevant public health information for other states planning to restructure child welfare services. The use of propensity score methods within a prospective cohort design has the potential to produce rapid expansion of the research base on this practice model and its mechanisms of change.